An ethereum.org tutorial token deployed with no name and no symbol, with a fixed supply, allowances and approveAndCall.
Historical Significance
This is the tutorial revision that added delegated spending, and it did it with approveAndCall: the allowance is set and the spender is called in the same transaction, so a contract learns about its allowance at the moment it is granted. It solved the problem ERC-20's plain approve leaves open, that a contract cannot notice an approval, and it was dropped from the standard anyway because it requires the spender to be a contract. The idea returned years later as ERC-777 and ERC-1363.
This deployment left the name and the symbol empty. Both are set once in the constructor and no function changes them, so the token has no display identity of any kind and never will: a wallet holding it can only ever show its address.
Context
By late 2016 ERC-20 had settled the interface a token was expected to answer, and the ethereum.org tutorial was still where most people copied one from. OpenZeppelin's contracts were not yet the default, so the code behind a token of this period is usually the tutorial's, with the constructor arguments changed and nothing else.
Token Information
Key Facts
Description
A fixed-supply token supporting transfers and third-party allowances, plus approvals that call back into the spending contract. Deployed September 2016 by 0x8bba7755e37421b75174bd531ff45b3a02332606.
Source Verified
Historian Categories
Heuristic Analysis
The following characteristics were detected through bytecode analysis and may not be accurate.
DAO Fork Era
The controversial fork to recover funds from The DAO hack.
Bytecode Overview
Verified Source Available
Source verified through compiler archaeology and exact bytecode matching.
View Verification ProofShow source code (Solidity)
// Submitted by EthereumHistory (ethereumhistory.com)
contract tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData); }
contract token {
string public standard = 'Token 0.1';
string public name;
string public symbol;
uint8 public decimals;
uint256 public totalSupply;
mapping (address => uint256) public balanceOf;
mapping (address => mapping (address => uint256)) public allowance;
event Transfer(address indexed from, address indexed to, uint256 value);
function token(uint256 initialSupply, string tokenName, uint8 decimalUnits, string tokenSymbol) {
balanceOf[msg.sender] = initialSupply;
totalSupply = initialSupply;
name = tokenName;
symbol = tokenSymbol;
decimals = decimalUnits;
msg.sender.send(msg.value);
}
function transfer(address _to, uint256 _value) {
if (balanceOf[msg.sender] < _value) throw;
if (balanceOf[_to] + _value < balanceOf[_to]) throw;
balanceOf[msg.sender] -= _value;
balanceOf[_to] += _value;
Transfer(msg.sender, _to, _value);
}
function approve(address _spender, uint256 _value) returns (bool success) {
allowance[msg.sender][_spender] = _value;
return true;
}
function approveAndCall(address _spender, uint256 _value, bytes _extraData) returns (bool success) {
tokenRecipient spender = tokenRecipient(_spender);
if (approve(_spender, _value)) {
spender.receiveApproval(msg.sender, _value, this, _extraData);
return true;
}
}
function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
if (balanceOf[_from] < _value) throw;
if (balanceOf[_to] + _value < balanceOf[_to]) throw;
if (_value > allowance[_from][msg.sender]) throw;
balanceOf[_from] -= _value;
balanceOf[_to] += _value;
allowance[_from][msg.sender] -= _value;
Transfer(_from, _to, _value);
return true;
}
function () {
throw;
}
}External Links
Related contracts
TT
Same eraA fixed-supply token with direct transfers only, deployed July 2016.
0xf78bdd...f9d225July 20, 2016shares
Same eraAn early on-chain corporation contract by cryptonomica.net, representing company shares as ERC-20 tokens with embedded voting — deployed hours before the DAO ha
0x684282...9a33b5July 20, 2016MyToken
Same eraAn ethereum.org tutorial token deployed with no name and no symbol, that tracks spending against approvals rather than decrementing them.
0x0eb106...9be583July 23, 2016ReplayProtection
Same eraAlex Van de Sande's post-DAO-fork ETH/ETC replay-protection splitter. Routes ether or ERC20 tokens to different recipients depending on which chain it runs on.
0x64668c...456541July 27, 2016BeerCoin
Same eraERC20-style 'I owe you a beer' IOU ledger by Nick Johnson (ENS). Each transfer creates a personal beer debt; obligations are tracked and transferable.
0x74c1e4...48f4acJuly 29, 2016Xi
Same eraDAO-era ERC-20-shaped token, May 2016. Symbol is the Greek capital letter Xi. Fixed cap 15,000; 1 token per 0.001 ETH via buy().
0xbe3dc7...cab9dfJuly 31, 2016